Hydraulic lift



C. J. BRISTOL HYDRAULIC LIFT Aug. 2v2, 1933.

Filed Deo. l5, 1930 Patented Aug. 22, 1933 nrnnnnrro LIFT Cyrus J. Bristol, Des Moines, Iowa, assigner to Globe Machinery c Supply Company, Bes Moines, Iowa, a Corporation of )iowa Application December 15, 1930 Serial No. 502,437

Claims.

This invention pertains to improvements in hydraulic lifts 01"' that type particularly adapted to be used for the purpose oi' lifting automobiles and the like, and ol' that type employing a ver- 5 tical cylinder mounted in the ground and having its upper end substantially level with the ground and employing a lift rod for supporting a suitable head on which tracks are mounted for supporting the automobile, and having hydraulic lo means for elevating the lift.

This type oi lift employs a piston at the iower end oi the lift rod, and a leather packing disc. Considerable dihiculty has been experienced on account of dirt and water collecting on the outer surface of the lift rod while in its elevated position Y while the automobile is being washed and cleaned, a portion ci the water and dirt being carried downwardly into the cylinder and past the piston, causing the leather packing to be rapidly worn out and destroyed, the water tending tc soalr the leather and harden the same.

It is, therefore, the object of my invention to provide in connection with the piston employed in hydraulic lifts of the type above described, means whereby the dirt and water will be collected in a suitable trap or container, and in connection therewith means whereby oil escaping past the piston will be collected and returned to the oil chamber.

My invention consists in the construction, ar-

rangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinaiter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is a side elevation oi one type oi' hydraulic lift, a portion o1" the cylinder being broken away to show the manner in which my improvedY piston is mounted therein.

Figure 2 is a detail sectional View, taken on the line 2 2 or Figure 1; and

Figure 3 is a detailsectional view, taken on the line 3--3 of Figure 1. Referring to the drawing, 1 have used the reference numeral 10 to indicate a storage tanker chamber of the usual construction, for the lifting fluid, such as oil, the upper end of the member 10 having an upwardly supported cylinder 11, the top end oi which terminates a slight distance above the ground surface and is provided with a bushing 12, said bushing being detachably secured in position by means of bolts 13 and nuts 14. The bushing 12 is preferably formed l*with a downwardly extending flange 15 project- (Cl. 25d-433) ing downwardly into the upper end of the cylinder 10 in the manner clearly illustrated in Figure 3.

Slidably mounted within the cylinder 11 is a piston 15 having an upwardly projecting skirt 17, 60 the periphery of said shirt being provided with a of annular grooves 18, the central portion of the under surface of the piston head having a boss 1e to which a flexible disc 2G is secured, the edges of said disc being provided with a downwardly and outwardly extending portion 21 to form a packing lor the piston and designed to engage the inner surface oi' the cylinder 11 in the usual manner. A metal disc 22 is mounted lent to the under surface or 'the member 20, 70 and preferably provided with a downwardly extending nange of smaller diameter than the member 21.

Bolts are provided iorr clamping the discs 20 and and the boss 19 together.

The boss 19 provides an annular space 25 between the disc 2o and the lower surface of the 16. The head 16 is provided with an opening in which is mounted a vertically arranged overilow pipe 26.

Slidably mounted in the bushing 12 is a hollow lift rod 27 having its lower end resting on the piston head 16 and within the skirt 17, in the manner clearly illustrated in Figure 3, the thickness of the skirt 17 being substantially equal to 85 the thickness oi' the flange 15.

` Ey this construction it will be seen that an -annular space 2S is io" led between the inner face of the piston 11 and the outer face of the lift 27 above the upper edge of the slrirt 17 and below 90 the 'lower edge. of the bushing 15.

Openings 29 are provided in the liit wall, whereby the space 28 is communicated with the interior of the said liftl rod, the openings 29 being mounted above the upper edge oi the skirt i7 and .95 above the upper end oi the overflow pipe 26, the space in the lower end oi the lift rod 27 below the upper end oi the pipe 26 forming a trap for receiving water and dirt.

In the practical operation it will be seen that if the piston 16 is at its lower limit of movement, with the lifting head 30 resting on the top edge of the bushing l2, and assuming that the hydraulic Yfluid is forced upwardly in the lower end of the cylinder to engage the lower end or the piston 16, then the said piston will be elevated until the upper edge of the skirt 17 engages the under edges of the ilange 15.

As the fluid is applied to the under surface of the piston usually a small amount of the fluid,

packing 20 and past the outer surface of the skirt 17 into the compartment 28. As the piston reaches its upper limit any oil collected in the compartment 28 will ow through the openings 29 into the trap, and thereby prevent the said oil from being squeezed upwardly between the bushing 15 and the outer surface of the lift rod.

Openings 31 are provided for receiving a suitable pin, which is passed through two of the diametrically opposite openings in the upper edge of the bushing 12 to lock the lift against-'accidental movement downwardly. Theplacing of this pin in position usually carries '1a. certain amount of dirt into the interior of the lift rod, a portion of which will be distributed over the outer surface of the said rod and carried'inwardlyas the said rod is moved downwardly, said' dirtcollecting in the compartment 28. Oftentimes the automobile is washed while supported in its elevated position, the water collecting on the outer Ysurface of the piston. A- portion of this is Valso drawn into the compartment 28. This water 'and Adirt will be'Washe'd-into thetrap through the openings 29 Vby the-inflowingA oil'which escapes aroundthe piston, thereby preventingthedirt -and oil from being forced downwardlyaround the outer surface of the piston skirt into-engagement with the outer surface of the-a-nge 21,'which heretofore has been very troublesome, especially whenthe'upper edge of the skirt 17 is allowed to make engagement'nwith the under surface of vthe'ilange 15 iniwhicha tremendous pressure is created andthe tendency is to force grit Aand water-downwardly around the outer edge of the skirt.

By providing the openings 29 this pressure is limited, inasmuch as the oil and water 4will flow 'freely' into the trap by gravity-beforey the piston reaches its upper-limit `of movement, the lower `end of thev openings 29 preferably being slightly below the upper edge-of the skirt-1'?.

' The 4annular grooves 18 assist in-collecting 'any water or grit that mightV otherwiseV have a tendency to move downwardly pastthe piston skirt as the same is being elevated. -Thishwater and vdirt is vmoved upwardly by `oilmoving upwardly past the piston-skirt.

yWhen the piston has'been returned to its lower `limit of movement the head 30 rests on the upper edge of the bushing 12 with the piston slightly above the lower ends of the cylinder. this timeis/collected into the Vchamber'lO, and any oilewithin the lower endy of the 4member 27 Iand above the upper end-of the'pipe 26 will 110W downwardly through the pipevinto the Vrecess Y25 and past the outer edge of the'packing 21,

la partial kvacuum being created4 below theA piston as the oil inv the lower end of thecylinderpasses intothe chamber 10, causing said surface oil to be sucked past the packing 21. It will readily be seen that any` water or dirtwill be collected Vin the lower end of the trap, which 'may be removed at any time desired throughthel end of the lift rod.

Oil at lliftrod, anoverilow pipe mountedin'thepiston, and a i' lex-iblev Adisc secured toy the 'lower surface of saidpiston, having itsperipheral edge'turned,

Vwhich is preferably oil, will be squeezed past the inder, a piston therein, a hollow lift rod carried by said piston, of smaller diameter than the cylindex', a bushing in the upper end of said cylinder for slidably receiving said lift, said lift having an opening communicating its outer and inner surfaces, said opening being. positioned adjacent kto the upper edge of? the said;` piston and above the lower end of said lift rod, an overflow pipe mounted in said piston, and a ilexible disc adjacent to the lower end of said piston and 85 adjacent to the lower end of said overflow pipe. -'2. `lla-hydraulic lift comprising a vertically arranged cylinderhaving a bushing at its upper end,.a1piston slidably mounted in said cylinder. .havinganvupwardly projecting skirt, the outer surface of said skirt being provided with an annulargroova' a hollow lift rod slidably mounted Vin said bushing and carried by said piston, said rodhaviing an opening communicating its outer and inner surfaces, said opening being above the loweren'd kof--said' lift rod and 'substantially even vwith-theupper edge of said skirt,an overflow vpipemounted in said piston, Khaving 'its upper end slightly-below said opening, andmeansifor closing the lowerend of said-overow pipe asO0 'fluid pressure isapplied to' the' lower end of said piston.

3. Ahydraulic' lift comprising an upright cylinder having -a bushingv in' its upper end, va piston slidably mounted Aiii-said cylinder, Ahavingv an"555 upwardly projecting skirt,-a hollow liftl rod slid- --ably mounted f in saidbushing,y having its lower `end resting ywithin said skirt, said ro'd Vhaving an opening communicating between its outerand -inner surfaces, said opening being'substantially H0 Avveven -with* the upper -edge of said skirt, vanoverflow Apipe mounted in thepiston; havingits upper f--end a slight! distance below vsaid openingfand its lower endcommunicating-"withl they spacebef =lewthe under surface of said piston, and' means" 115 for automatically' closing thel lowerend v`ofl said l' overflow f pipe when vpressure -is l'applied to the -lower-end ofsaid piston.

- inder havingv a Ibushingin its upper end, a hollow x20 I lift rod slidably mounted insald bushing and supported on said piston,l said lift rod^having -an opening communicating between the Vinner and outer surfaces of said lift rodfandabove'its.) -lowerend, to" for-mv' a chamber for collecting dirt 125 and water clinging- -totheouter` surface"of"said downwardly and outwardly to f form "a packing ange,saiddisc bei-ng"adapted` to closethe" lower end of said overflow' pipe aspressure-is' applied to the lower end 0fsaid-cylinder.

5. A hydraulic lift comprising a cylinderapis- .ton insaid eyunderpaehouow-1in `rod carried by'135 said piston, having'an opening communicating'betweeniiits outer and innersurfaces, said open-ings lected in-the lower end of said-echambereand excess oil will be allowed to flow .downwandly through said overowpipe yinto the lower end of said cylinder.

V6. vA hydraulic'lift comprising a cylinder, al50 piston slidably mounted therein, having an upwardly projecting skirt, annular grooves in the outer surface of said skirt, the central portion of the under surface of the piston having a downwardly extending boss, a flexible disc supported adjacent -to the under surface of the said boss and having its peripheral edge turned downwardly and outwardly to form a packing and provide an annular space between said disc and the under surface of said piston, a hollow lift rod carried by said piston, having an opening communicating between its inner and outer surfaces, and an overflow pipe projecting upwardly into the lower end of said lift rod, having its lower end communicating with the annular recess below said piston.

'7. A hydraulic lift comprising a vertical cylinder having a bushing in its upper end, a piston slidably mounted in said cylinder, having an upwardly projecting skirt, the outer surface of said skirt having annular grooves, a hollow lift rod slidably mounted in said bushing, and supported by said piston, said lift rod having a series of openings, the lower openings being substantially even with the top edge of said skirt for communicating the inner and outer surfaces of said lift rod, the upper openings being designed to receive a pin for limiting the downward movement of said lift rod, said piston being provided with an overflow pipe projecting upwardly into the lower end of said lift rod, and means for closing the lower end of said overflow pipe as pressure is applied to the lower end of said piston.

8. A hydraulic lift comprising a vertical cylinder, a piston slidably mounted in said cylinder, a hollow lift rod carried by the upper end of said piston, said hollow lift rod being smaller in diameter than the cylinder to provide an annular space between the lift rod and said cylinder for the collection of water, dirt and similar substances, said hollow rod having an opening connecting its inner and outer surfaces, said opening being above the bottom end of said rod, whereby a chamber will be formed in the lower end of said rod below said opening, an overflow pipe supported in said piston, projecting upwardly into said lift rod with its upper end terminating below said opening, whereby fluid may ilow from the annular space around said lift rod through said opening into said chamber, and from said chamber through said overflow pipe to the cylinder, which may be beneath said piston as the piston is moved upwardly, and means for closing the lower end of said overflow pipe when pressure is applied to the lower end of said piston.

9. A hydraulic lift comprising a Vertical cylinder, a piston slidably mounted in said cylinder, a hollow lift rod carried by said piston, said piston and lift rod having an annular space between the lift rod and said cylinder near the lower end of said lift rod, an opening connecting the inner and outer surfaces of said lift rod, located above said piston, whereby a chamber will be formed below said opening and within said lift rod, an overflow pipe carried by said piston, and means for closing the lower end of said overflow pipe when pressure is applied to the lower end of said piston.

l0. A hydraulic lift comprising an upright cylinder, a piston slidably mounted in said cylinder, a hollow lift rod carried by said piston, said 105 hollow lift rod and cylinder being provided with an annular space between the hollow lift rod and the cylinder near the lower end of said lift rod, an opening connecting the inner and outer surfaces of said hollow lift rod, an overflow pipe 110 in said piston having its upper end terminating below said opening, and means for closing the lower end of said overow pipe when pressure is applied to the lower end of said piston, and permitting it to open as said pressure is released.

CYRUS J. BRISTOL. 

